Conventionally, a pair of right-and-left front side frames provided on a front vehicle body of a vehicle are connected to the front side of a dash panel, each rear end part thereof extending near the front end of a floor panel rearwardly along a slant portion of the dash panel and joined to the dash panel and the floor panel from the outside of a vehicle room. In order to decrease a collision load against passengers in a vehicle frontal collision, a midway portion of the front side frame bends in a vehicle width direction at the front of the dash panel, and such deformation of the front side frame thus absorbs a collision energy of the collision load.
A front vehicle body structure of a vehicle disclosed in Japanese Patent Laid-Open Publication No. 2011-088597 comprises a front side frame which forms a closed cross section extending in a vehicle longitudinal direction; and a reinforcing member which reinforces an inward side wall of the front side frame, in which a pair of front and rear outer beads extending vertically are provided at an outward side wall of the front side frame so as to project into the closed cross section, an inner bead extending vertically is provided at the inward side wall of the front side frame at a position corresponding to a middle position between the pair of outer beads so as to project into the closed cross section, and each of the beads are formed in a zigzag manner in a plan view.
Thus, in a vehicle frontal collision, the pair of outer beads are respectively deformed so as to bend into a V-shape, and the inner bead is deformed so as to bend into a reverse V-shape, thereby improving collision energy absorbing performance of the front side frame.